Horses evolved as grazing animals, and their teeth are perfectly adapted for that purpose. The forward teeth, known as incisors, function to shear off forage. The cheek teeth, including the molars and premolars, with their wide, flat, graveled surfaces, easily grind the feed to a mash before it is swallowed. Like humans, horses get two sets of teeth in their lifetime. The baby teeth, also called deciduous teeth, are temporary.
The first deciduous incisors may erupt before the foal is born. The last baby teeth come in when the horse is about 8 months of age. These teeth begin to be replaced by adult teeth around age 2 1/2. By age 5, most horses have their full complement of permanent teeth. An adult male horse has 40 permanent teeth. A mare may have between 36-40, because mares are less likely to have canine (bridle) teeth.